


The Undertow

by natsume_kun



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Modern Setting, Because I Think It's Hot, Bookstores, Eruri Is Only A Background Ship But It's There, Erwin Smith Has Glasses, Eventual Romance, F/M, Fluff, Friends to Lovers, Humor, Levi Agrees, Literature Student Armin, M/M, Metaphors, Mikasa Ackerman & Levi Are Related, Mikasa and Levi Run A Bookshop, Ocean/Sea, Professor Erwin Smith, References to anxiety, Tooth-Rotting Fluff
Language: English
Status: Completed
Published: 2021-01-31
Updated: 2021-01-31
Packaged: 2021-03-17 19:40:43
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 7
Words: 8,612
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29105733
Author URL: https://archiveofourown.org/users/natsume_kun/pseuds/natsume_kun
Summary: Armin’s first memory of her is by the sea.It’s a faint memory from his childhood-- one that he struggles to remember, yet it is there, nonetheless-- just coursing below the surface.Armin is a literature student who moves back to Coast Sina for graduate school. When he starts to frequent the local bookshop where Mikasa worked, feelings gradually surface between the two of them. They don’t realize it until a pull from the waters below sweeps them both away.--or: the ocean/sea-themed arumika fic in which armin is a literature student and mikasa is a bookshop clerk and they bond over books, eruri’s shenanigans, their relationship with eren, and a cat.***edit: i finally drew fan art based on this fic so i've updated the ch. 7 notes with the link to that
Relationships: Levi/Erwin Smith, Mikasa Ackerman/Armin Arlert
Comments: 35
Kudos: 68





	1. Chapter 1

**Author's Note:**

> i remembered that ocean scene at the end of season 3 and i thought am i going to make a fic loosely based on those 20 seconds of arumika yes yes i am

> **undertow (noun)**
> 
> —An undertow is a strong current of water that is moving below the surface current and in a different direction to it. (Collins Dictionary)
> 
> —An implicit quality, emotion, or influence underlying the superficial aspects of something and leaving a particular impression. (Oxford Languages Dictionary)
> 
> —If there is an undertow of a feeling, that feeling exists in such a weak form that you are hardly aware of it, but it influences the way you think or behave. (Collins Dictionary)

* * *

Armin’s first memory of her is by the sea.

It’s a faint memory from his childhood-- one that he struggles to remember, yet it is there, nonetheless-- just coursing below the surface.

Armin sits on the shore hugging his knees, the tide shyly tickling his tiny feet as the cold sea breeze hits his skin. Armin shudders in between sobs, remembering how his grandfather wouldn’t wake up that morning. He is cold as warm tears fall down his cheeks.

Lithe steps soon approach him-- digging into and brushing against the sand. Armin turns. Just a few paces away from where he sat, he finds a little girl burrowing a cupped palm into the wet sand of the shore. And in her other hand, she carries a bright green plastic bucket with a yellow handle. 

Armin watches silently as her long dark hair sways in the wind, mimicking the waves before her. The little girl picks up a shell from the hole she had dug into and sets the bucket down on the sand. She cradles it in her hands, slowly turning the shell to examine it from all sides as she traced along its contours and hollows. Seemingly pleased with what she had found, the little girl smiles, her pinky finger daintily springing up as she pushes a tuft of hair behind one ear.

She soon takes notice of him-- realizing that someone has been watching. When she turns, Armin springs slightly from where he sat, hugging his knees closer to himself. The girl approaches, sitting on her legs merely a step away from his feet, and then gazes at him curiously-- fixated on the trail of tears on his cheeks. She briefly examines the seashell in her hand before turning back to face Armin. And then she gathers his hands, placing the seashell on his palms now cupped together.

She abruptly turns upon realizing someone had been calling out to her. She stands, hurriedly taking the plastic bucket by the handle before taking off.

Armin looks down at the seashell in his hands, fascinated as he begins examining and tracing along its sides just as the girl had done moments ago. 

He soon wipes his tear-stained cheeks against his sleeves.

***

“Is there a bookstore around here?”

“Yeah-- Kuchel’s. The only one nearby. It’s a second-hand bookshop. My friend Mikasa works there,” Eren says in between huffs, setting down another box of Armin’s books. “Don’t you have enough of these, though?” He reaches to knead an aching muscle in his back while catching his breath.

“Sorry, I know it’s a lot,” Armin says meekly, picking up a pile of his folded clothes from the trunk and arranging them in the wooden cabinet.

“Yeah, yeah. It’s fine. Anyway, you want me to show you around later? We could drop by Kuchel’s too.” Eren stretches out his arms.

“Sure. You mentioned a friend from there? Mikasa, was it?”

“Yeah. You know, I’m kinda surprised you guys never met when you lived here with your grandpa before.”

“Hm. We probably would have met had I stayed here longer. If only my grandpa…” He shrugs with a crooked smile. 

Something heavy hangs in the air.

“Anyway… what’s Mikasa like?”  
  
\--

The rattling of chimes fills the shop when Eren hastily slides the latticed door to widen the entrance. 

“Mikasa?” Eren calls out louder than was probably necessary.

Armin is drawn to the chimes by the door-- orange and purple seashells hanging from strings along with small fish-shaped bells-- some of the paint seeming to have already peeled off, hence revealing the shiny silver metal beneath.

The place is quaint. Wooden planks paneled the walls, floors, and ceiling. Small shelves, tables, and racks surrounded the aisle that led towards the till, while uneven towers of books emerged from cardboard boxes sitting right beside the counter. Light bulbs-- already yellowing in color-- hung from the ceiling while sunlight poured in from circular windows framed by green curtains. Armin takes it all in. The air is crisp with the scent of foxing paper and a whiff of salty sea breeze. He decides he already likes this place, thinking fondly about how it reminds him of a ship.

“Eren?” Someone calls out. A girl with short, chin-length dark hair emerges from behind the till, setting aside the paperback she had just been reading. Her eyes seemed to light up upon seeing Eren.

“Hey, I just came by to give Armin a tour around.” They both head towards the till. “He’s a friend who just moved here from the city. He starts grad school at Coast Sina University this month. Taking up Masters in uh...” Eren says uncertainly, looking towards him in question. 

“Literature,” Armin fills in.

“Right, literature. So, uh, he’ll probably be coming here often. He likes books. You like books.” Eren gestures towards Mikasa this time. “You two will get along just fine.”

“It’s really nice to meet you, Mikasa,” Armin says cheerily, giving her a tiny wave.

Mikasa briefly regards him with an aloof nod. Nothing more, nothing less.

Armin thinks he hears crickets, but it was probably just his imagination. It’s about mid-day, after all. _Too early for them to be up and chirping._

A stilted air hangs between them. Is this what Eren meant when he said they'll get along just fine? He definitely spoke way too soon.

Eren leans into the counter and visibly tugs on Mikasa's sleeve. “Hey! Say something,” Eren whispers harshly with a glare, albeit his pathetic attempt at whispering was loud enough for Armin to hear anyway. Mikasa furrows her brows at Eren, slightly irritated. 

Armin holds back an amused chuckle. _They seem close_.

“Hey, it’s-- it’s alright,” Armin interrupts their silent quarrel. “Eren’s right. I’ll probably be coming here a lot, so you and I have plenty of chances to talk. It doesn’t have to be now,” he says, beaming at her.

Mikasa meets his eyes for the first time that day. Her eyes are gray, reflecting her seemingly reticent nature. Armin thinks the color suits her perfectly.

“Alright,” Eren lets out an exasperated sigh as he glances at the wall clock behind the counter. “I have a shift coming up. Armin, just go ask Mikasa here if you need any more help with directions.” Eren shoots her a subtly threatening glare. “You can text me if anything important comes up. In the meantime, you two just-- just try to get along. Ok?” He pointedly addresses that last bit towards Mikasa.

“Anyway, I’m off.” Eren turns to leave the shop, coolly placing his hands in his pockets as he does so.

“Take care, alright?” Mikasa says, almost pleadingly.

“Eren--” Armin calls out hurriedly. “Thanks for helping me out. With the move and showing me around. I-- I’m really grateful,” he adds-- a smile easily discernible from his voice. Mikasa gives him the side-eye.

“Sure, sure.” Eren waves them off curtly and exits the shop. 

Another stilted silence. 

And then Mikasa sits back down behind the till, picking up the paperback she had been reading as if nothing had happened.

“Uhmm, I-- uh-- I’ll go take a look around.” 

Mikasa impassively nods from behind her book.

Armin wanders the place, navigating through the wooden shelves, tables, and racks. Occasionally, he would pick up a book that catches his eye, then flip through its pages and skim the descriptions printed on the back covers. 

He soon realizes he’s lost track of the time when the door chimes rattle and a pair of students-- still in their uniforms-- enters the store to browse through one of the racks. Not long after that, a man enters the store, huffing as he carries in his arms a cardboard box similar to the ones that had already been set beside the counter.

“That’s the last of this week’s pickup,” he says, setting the box down by the till. He had dark hair-- just like Mikasa’s-- albeit he was of a distinctly shorter stature.

“I’ll start sorting through them,” Mikasa responds with a nod. She places her paperback on a shelf behind the counter.

Armin notes the air of similarity between them-- how they both seemed to exude an aura of cold reticence.

The man takes out a cutter from the pocket of his apron and kneels in front of the new box he had picked up. Thumbing against the side of the box cutter, he raises its blade with a jagged clicking sound. Just as he begins to lower the blade onto the box, he glances briefly towards his periphery and meets Armin’s eyes. 

Armin slightly springs up in fear. He instinctively hides his face behind the book he had been flipping through. The man squints at him with cold, sharp, catlike eyes. Armin’s not so sure if that man was scrutinizing him out of curiosity or they simply wanted to kill him. Somehow, it feels like both. 

Armin nervously swallows down a lump in his throat.

Great. Just when he had already decided he liked this place, it seems everyone who worked here despised him for some reason. 

Thankfully, the man had gone back to his task-- slicing a clean line of tape on top of the box-- by the time Armin decided to peek out from behind his book. He clutches a hand at his chest and sighs in relief. When the man finally disappears into the doorway behind the counter, Armin approaches the till.

“You know, if you’re not going to buy anything--”

Armin sets a book down on the counter.

Mikasa sighs as she begins to punch some buttons on the cash register. She wordlessly takes the bill Armin had also set down on top of the counter. The cash register dings as it opens and Mikasa hands him his change. She takes out a paper bag from behind the counter and places the book inside, deftly sealing the opening with tape before handing it to him. 

“Thanks, Mikasa,” Armin says with a crooked smile, hugging the paper bag close to his chest.

“Sure,” she says impassively as she moves on to her next task-- picking up one of the open boxes and setting it down on a chair behind the counter. Before finally sorting through the newly-picked up books, she tucks a tuft of hair behind one ear. 

Something about such an ordinary gesture strikes him as distinctly familiar. _Huh._ Armin tilts his head curiously.

Armin soon turns to leave the store, thankful that he had gotten out of that place still in one piece.

And yet, despite the staff’s cold demeanor towards him, what he had declared earlier still rings true-- that he’ll find himself coming back here again-- and probably for far more reasons than he is keenly aware of.


	2. Chapter 2

It isn’t until about three months of awkwardly terse exchanges in the shop later that Armin manages to hold a proper conversation with Mikasa. It was just as he had guessed-- bringing up _Eren_ makes her just a tad bit more talkative than usual.

“Yeah. I lived with the Jaegers for a while. It was after my parents got into an accident. Levi’s a distant relative who came here around the time I was in high school. He took me in then,” Mikasa deadpans as she mechanically arranges a set of newly-picked up books into the shelf.

“That explains why you two seem so close then. You two grew up together in this place,” Armin says, slightly wistful. “I used to live here in Coast Sina too-- although... that was only for a short while-- when I was kid. That’s also when I met Eren. I wonder, though… what was he like growing up?” Armin looks up at her, idly thumbing the page of a book while sitting on a wooden crate.

“Loud. Always got into fights at school. I’d wait for him because he kept on getting detention.” A furtive smile.

Armin senses a hint of endearment in the way she spoke. He closes the book and looks up at Mikasa attentively, head cradled in his palm.

“I can see that happening.” He nods. “Eren really does have a way of stirring up trouble wherever he goes. And despite that, I’m still glad we became friends. We met because I used to get bullied by the bigger kids here. Then Eren jumped in one day to save me,” Armin recalls fondly. “Although… I feel like he’s changed a lot these days. I mean, I wasn’t here for the most part to witness how that could have happened… and we could have just drifted apart in all those years we didn’t really see each other-- so maybe it’s just me. But anyway, I feel he’s more… distant.” He shrugs.

“I feel that too.”

“You-- you do?”

Mikasa nods, wiping off some dust on a paperback using a cloth. Her expression turns pensive.

“You know... we… we went to prom together in high school,” she says timidly.

“Oh?” Armin gapes, intrigued.

“We kissed once. And then a week later, he was kissing another girl.” 

“Oh. That’s--”

“Levi punched him in the face.”

“Wha--”

“Then I punched Levi in the face. He brought home some booze that night and invited me to drink with him.”

Armin gulps. So maybe he was right after all to fear for his life when he first set foot in this place.

“After that, I decided to help him out with this bookshop. I picked up reading somewhere along the way-- at first just so I could keep my mind off of things.”

“I see… then what happened with Eren after that?”

“He eventually said sorry and I forgave him.” Mikasa visibly sighs in exasperation upon recalling the memory. “Levi still wants to punch him, though. I mean, I also kind of do. Sometimes.” She shrugs.

“How do you… how do you feel about Eren now?” Armin asks cautiously.

Mikasa mulls over it, momentarily hanging her fingers on the wooden plank of the shelf.

“Well, I forgave Eren in the first place because I do love him,” she says plainly, moving on with her task and deftly placing another set of books on the shelf. “I’m not really sure how to put it, but… I don’t really see us becoming lovers or anything like that anymore. I don't think we need to be. He’s... he’s a really close friend. And I love him. That’s all there is to it.” ‘ _Is there a word for that?’_ Mikasa seems to ask, tilting her head in contemplation. “Sorry, I’m not really sure if I’m making sense.” Mikasa turns to him. “I’m not really that good with words.” 

“That’s ok. I… I think I get it.” He nods amiably.

“Anyway, don’t you…” Mikasa steps a few paces away from the bookshelf to examine her handiwork. “...don’t you have somewhere else to be?” Her tone lacks the cold hostility Armin thinks should have been there.

Armin shakes his head. “Not really. All my classes for the day are over. And I only have a thesis consultation with Professor Smith tomorrow. And besides… I really like this place.”

“Professor… Smith?” Mikasa turns to him with a questioning look.

“Oh, he’s my thesis adviser.”

Mikasa hums contemplatively.

“Is he, by any chance… tall and blonde?” she says, curiously eyeing the shelf. “Blue eyes, wears glasses sometimes, and smells like… like he bathes in Axe body spray or something?” 

“That’s-- wait, you know him?!” Armin gapes in surprise.

“His name is… Erwin, right?”

“Yeah, that’s him!” Armin nods enthusiastically.

“He’s a regular here. Levi gives him discounts,” she states casually.

“Oh. How do you get discounts here?”

“That’s--” 

They both turn when the shop door suddenly slides open with the rattle of chimes. 

Levi enters the store and acknowledges Mikasa with a nod. He briefly glances at Armin before making his way to the till.

Mikasa gives Levi a furtive glance.

Then she turns towards Armin.

“I think… I’d better tell you next time,” Mikasa says.

 _Next time_ , Armin echoes in his head. He smiles.

***

“The record book? It’s on my desk. I was checking the schedule of book pickups for next week,” Levi says, dusting off the till.

Mikasa gives a perfunctory nod. She makes her way to Levi’s bedroom and heads towards the desk. Having found the said record book, she notices a pair of gold-rimmed spectacles on top of the bedside table. Mikasa picks it up, squinting curiously as she examines it.

 _Weird. Did Levi wear glasses now?_ Maybe he merely used them for some nighttime reading in his room-- hence why she never actually saw Levi wear these. Still, it probably wouldn't hurt to ask. It's just Levi, anyway.

With the record book in one hand and a pair of glasses on the other, she heads back to the store.

“I didn’t know you wore glasses now,” Mikasa says plainly, slightly raising the gold-rimmed spectacles in her hand.

“What glasses are you spouting about?” Levi turns.

And then he gapes in horror upon recognizing the pair of spectacles in her hand.

“Shit. Where did you--” Levi trails a palm down across his face with a frustrated sigh. “Give that here,” he says sternly, seizing the glasses from her. “Watch the shop now. I’m going out earlier today.”

***

A few days later, Mikasa recognizes one of their regulars in the bookstore-- he’s a tall blonde man named Erwin. _Erwin Smith_ \-- She knew his name because Levi had talked to this man several times before. On the regular, Mikasa hardly paid him any attention whenever he came to the store. Customers are just customers and work is just work, after all. 

However, when Erwin Smith comes in wearing glasses today, Mikasa is convinced she recognizes those same gold-rimmed spectacles.


	3. Chapter 3

“Mikasa, do you have a favorite book?” Armin says, sitting at the foot of a bookshelf as he hugged his backpack close to his chest.

“A favorite…” Mikasa huffs as she sets a box down on the spot beside him. “...I’m not sure.” She grabs a pile from the box, then examines the cover of each before arranging them respectively on the shelf. "There’s… well, there’s a lot to choose from.”

“Oh, of course.” Armin curiously peers inside the box.

“Let me see…” Mikasa hums. “How about… you can tell me yours first. I’ll think of something in a while.”

“Ok,” he nods amiably. “Well, the thing is... I do have a lot of favorites too… so I get why it’s so hard to choose. But if I _really_ had to choose right now, I guess I’d go with… Oh!” Armin lights up. “I have it here, actually. Professor Smith let me have his copy.” He zips open his backpack and rummages through his things. “It’s called The Great Passage by Shion Miura.” Armin holds it up to her. The cover features a scrapbook-like collage of paper waves made out of paragraphs, and then atop sits a bright red sun; the entire composition playfully resembles a view of the sun from the seashore as it sets on the horizon.

“Shion Miura…?” Mikasa echoes with piqued interest, furrowing her brows as she takes the book from him. She turns it in her hands to read the description on the back cover. “Oh. I’ve read this novel.” There’s a lilt in her tone.

“What? Really?!” 

“I’ve read this in Japanese. It’s entitled _Fune wo Amu_.” Mikasa skillfully pushes the box with her foot to make some space beside Armin. “I didn’t know it had a translated version.” Mikasa settles down beside him. “Huh. You know what, actually…” She turns to face Armin. “...You remind me a lot of the protagonist-- Majime.” 

Armin chuckles playfully at that. “Do I… do I seem like the type to make cheesy whimsical metaphors?”

“Well… yes.” Mikasa nods candidly. “...And it’s not hard to imagine you writing a cringey love letter like the one he wrote for Kaguya.”

“What?” Armin laughs. “Come on, I’m not taking up literature only to be told I’d write cringey love letters.” He looks at Mikasa fondly.

“I mean, Majime was a linguistics graduate-- and even then, he wrote a terrible one,” Mikasa says matter-of-factly with a shrug, as she flips through the book. 

“Well, that’s true, but...” Armin trails off as he bashfully hugs his backpack closer to himself, watching Mikasa trace her fingers along the smooth pages of the book. She then delicately pushes a tuft of hair behind her ear.

“Hm…? But what?” Mikasa turns to face him.

“Oh. It’s--” Armin lightly springs up in his seat. “--it’s nothing. I forgot what I was about to say,” he muffles hastily into the backpack, making himself smaller as he hides his face behind it.

“Armin? Are you… are you ok?”

“Yeah, I-- I’m fine.”

“Hm. Ok.” Mikasa nods, handing him back the novel. She stands up and makes her way towards the till.

Armin slowly loosens up as he peers curiously towards where she had gone.

Mikasa rummages for something behind the counter and then shortly returns to settle on the spot beside him.

“Here.” Mikasa holds out a book towards him. “It’s the version I read. This here is the title.” She traces down vertically along a line of characters printed on the book. “These two characters here are called kanji. These ones with simpler strokes are hiragana. This character here means ship, while this one here could mean a compilation of text or to weave. All together, the entire title literally translates to weaving a ship.”

“Weaving a ship…” he echoes with fascination. Armin gingerly traces a line down the characters, his fingers lightly brushing against hers for a moment. “...I think that’s really fitting.” He gives Mikasa an appreciative glance. “Thank you for showing me this.”

Mikasa gives him a perfunctory nod. “Hm. Come to think of it…” She muses at the book. “...I guess this might be my favorite book after all.”

**Notes for the Chapter:**

> *the book i refer to in this chapter (the great passage by shion miura) is an actual novel that's been translated from japanese to english. it's also been adapted into an anime called fune wo amu. just for more context, the protagonist is a dictionary publishing editor named majime and his love interest is a girl named kaguya. he confesses to kaguya by writing a terrible love letter in which he uses very eccentric metaphors + quotes a lot of really confusing classical poetry.
> 
> here's a link to an image of the actual cover which i described in this chapter: [the great passage by shion miura](https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcTjgupcZaDm1O-5KCiekwDiMNeNzAd9rxI_LaO3NPr2CBKBqVjL)


	4. Chapter 4

“Where the fuck is that cat?” Levi says, visibly distraught as he peers into a bottom shelf.

“Umiiiiii!” Mikasa calls out in a singsong voice, opening and closing the counter’s cabinet doors behind the till.

The door chimes soon rattle and in comes Armin with his typical vibrant demeanor. A few shelves, racks, and tables had been moved from their usual spots-- the ones in the center now aligned randomly instead of being lined perfectly parallel to the aisle.

“Well, I’ll be damned if that cat actually got out of this place.” A grumble from behind the shelves.

“Umiiiiiii!” Mikasa emerges from the till. She turns to face the aisle. “Oh. Armin.”

“Is this… is this a bad time?” Armin says sheepishly, scanning the place as he approaches the till.

“We can’t find our cat.”

“Oh. I didn’t know you guys had a cat. What does your cat look like?”

“Black fur and blue eyes. Has a fish-shaped bell on his collar. His name is Umi.” Mikasa hums thoughtfully. “By any chance, have you seen him outside on your way here?”

“Oh...” he muses. “Sorry, I don’t think I’ve seen him around.”

“Hm. That’s fine.” Mikasa regards him with an understanding nod.

“I-- I can help you look, though.” Armin scratches his head sheepishly.

“Oh. You don’t have to.”

Armin shakes his head. “It’s fine, really. I mean-- cats are always worth the trouble.” 

“Well… if you really want to, then.” Mikasa shrugs. “This is the last room in the house we haven’t finished checking. I last saw him in Levi’s room, so we searched the rooms at the back first. We couldn’t find him there so we thought he might have gone here to the store.”

“I see. So this place is most likely where he is, then-- that is if he really hasn’t gone outside.” Armin nods in understanding. “I’ll start searching.”

He thoughtfully scans the interior of the place again. _Let’s see… if I were a cat, where would I go? Perhaps some place where I’m almost certain no one would bother me? Maybe a place of high elevation?_

Armin catches a slight movement from his periphery, accompanied by a faint rattle. His eyes wander towards the cardboard boxes sitting beside the counter, closing in on one particular box with its flaps loosely closed.

_Or maybe not._

Armin curiously approaches the box, then cautiously opens its flaps. He gapes in pleasant surprise. There, he finds a black cat slumbering peacefully with its head laid on a book.

“Umi!” he cries out brightly.

“What?” Mikasa hurriedly approaches him. “Oh. You found him.” She sighs in relief. 

“Levi, Armin's found Umi,” Mikasa calls out.

“God fucking finally,” he sighs.

***

“That boy who always comes around-- he seems more pleasant than that shithead Eren,” Levi spontaneously remarks in the middle of wiping dust off the shelves.

Mikasa sighs, looking up from the paperback she had been reading. _This again_. She rolls her eyes. “Eren isn’t that bad. He… he can be nice.”

“You call that piece of shit nice? Last time he set foot in this place, he almost killed Umi.”

“He didn’t mean to hit the bookshelf, alright? It was an accident.” She follows with an exasperated sigh.

“Accident my fucking ass.” He picks up a box at the foot of a shelf and heads for the till.

“And besides… you only like Armin better than him because he reminds you of Erwin,” she says offhandedly.

Levi ceases just right in front of the counter and stares daggers at her. 

Mikasa returns his glare with a look of cool indifference.

“I know I’m not wrong,” she says nonchalantly, returning her attention to the paperback. 

Levi drops the box with a menacing thud. Mikasa raises an eyebrow at him coolly.

“Go feed and give Umi a bath tonight.” A stern order.

“If you and Erwin are dating, I honestly don’t mind.” Mikasa gives him a nonchalant shrug.

“Shut up, brat.”

***

“Oh!” Mikasa yelps as Umi suddenly jumps out of her lap when the door chimes rattle. Armin’s here.

“Oh, hello there, Umi!” Armin greets, pleasantly surprised when the cat begins circling around his feet. Umi fondly nuzzles his head against Armin’s leg. 

Armin chuckles as he lowers himself to give Umi an affectionate scratch on the head.

Amused, Mikasa watches from behind the till, taking notice of how Umi already seems to like Armin more than Eren. Umi never bothered to approach whenever Eren would try to call out to him. And whenever Eren would try to pick him up during the times Mikasa would take the cat out on a walk, Umi would get all frantic-- struggling in Eren’s grasp and baring his claws trying to scratch him. 

To be fair, Eren _did almost_ kill the cat, albeit it was clearly an accident. Good thing Levi dove under the bookshelf in time to shield a sleeping Umi. Mikasa wonders if even in Umi’s drowsy state, he was aware that the accident was caused by Eren. 

Mikasa smiles at the thought. Over time, it seems like Umi is taking more and more after Levi.

***

“So why is he called Umi?” Armin picks up the cat and sets it down on his lap, his legs dangling from the porch.

“I named him that.” Mikasa muses, watching the waves crash gently on the distant shore as she sits beside him. “Levi had found him sleeping in one of the bottom shelves-- the space after the bookend just enough for Umi to fit. Levi beckoned for me to come see and then asked me if we should keep him. When he opened his eyes, it just suddenly came to me-- that word: _umi._ I think I might have said it out loud too. I remember learning it from my mother-- on one of those times we had gone for a walk on the shore. She said it means the sea or the ocean. It’s-- oh, wait here. I’ll go get something from the house.” Mikasa briefly disappears into the room behind them, then returns a few moments later with a notebook and a pen. She settles down on her spot beside Armin on the porch and writes on the back page. “It’s written like this.” She points the tip of the pen to the character she had written.

“Ah, this is… kanji, right?” he says in recognition. Armin leans in closer to examine the character as he gingerly combs through the cat’s fur with his fingers.

Mikasa watches him silently and then hums in realization. “Huh. You’ve got eyes like Umi.”

“Oh.” Armin feels a rush of warmth in his cheeks when their eyes meet. “Maybe…” he lets out an awkward chuckle. “...Maybe that’s why we get along so easily. Maybe he naturally thinks I’m family.” 

Umi lets out a soft mewl when Armin gives the cat a gentle scratch on the head.

“Hm.” Mikasa tilts her head questioningly at him. “Armin, do cats see blue?”


	5. Chapter 5

“So that’s how you fold a paper boat.” Mikasa holds out an origami boat in front of Armin.

“Right. Uhm… sorry. I didn’t get that. Can you show me again?” Armin says, visibly distraught. He scratches his head nervously while forcing a sheepish smile.

“Hm.” Mikasa tilts her head, observing him contemplatively. “You ok?” Mikasa sets the paper boat down behind them on the porch.

“Oh, it’s just-- I’m having a hard time focusing on… well, anything.” He sighs in defeat. “ It-- it’s nothing new though. It comes and goes.”

“Did something happen or…?”

“It’s-- Professor Smith’s come down with a fever. And I’m working as a faculty assistant for the literature department so… so they need me to fill in for his undergrad lectures for a few days. I guess I’m just…” Armin looks distantly at the shore. “...I’m really scared. What if I end up going in circles and… and I can’t explain the lecture well… and the students don’t get anything I’m saying because of that? What if they end up laughing at me or… like-- what if the professor scolds me exactly because of that? I mean, I know I’m nowhere near as good as him so… why choose me for this?” 

Armin heaves a weary sigh.

“I see. That’s--” Mikasa squints pensively. “Sorry, I… I’m not really good at these kinds of things.” She carefully ponders her words. “But... thank you for telling me. And if there’s anything-- oh. Give me a second.”

Mikasa disappears back into the house and soon returns with a card in hand.

“Here.” Mikasa hands him what appears to be a calling card. 

“Did you have a therapist back in the city?” Mikasa asks cautiously.

“Yeah.” Armin traces a finger idly over the embossed gold letters on the card. “But only for a short while-- mostly because I planned on moving here eventually after undergrad.”

“I see.” Mikasa hums. “Maybe he can help. Dr. Berner’s really pleasant and easy to talk to. He’s mine and Levi’s therapist.”

“Oh. That’s good. Thank you, Mikasa.” He glances at her with an appreciative nod.

Mikasa shifts in her spot on the porch to face Armin, and then gives him a gentle pat on the head.

Umi soon approaches from behind them to settle down on Armin’s lap. Armin and Mikasa briefly exchange amused glances. Armin lets out a playful chuckle as he gently pets the cat.

“So... how about that paper boat again?” he brings up, looking at Mikasa.

Before she could answer, Umi responds in approval with a peacefully reassuring mewl over the restful rhythm of crashing waves.

***

“Come here, you fucker.” Levi seizes Erwin by the collar to pull him closer towards himself on the counter. Levi looks up at him roguishly, then quickly snatches away his glasses as he trails his other hand down along Erwin’s chest. Then he playfully pushes Erwin away from himself with a mischievous laugh.

“Levi, what are you even--” Erwin chuckles, but soon trails off when he sees that Levi had donned on his gold-rimmed spectacles.

“Holy fuck. This shit’s gonna break my eyes.” Levi scans the room, holding the hinge of Erwin’s glasses between his thumb and forefinger. “So how do I look?” Levi asks, slightly lowering the glasses on the bridge of his nose as he peers up at Erwin from behind them. 

“Well, I can’t really tell, can I? I don’t have my glasses on,” Erwin says, raising an eyebrow playfully.

Levi sighs in exasperation as he tries to hold back a smile. “Fucker. You’re like inches away from my face,” he chuckles. 

“Alright. Fine,” Erwin says, reaching up to put a palm on Levi’s cheek as he leans closer. “You’re gorgeous,” Erwin finally answers with a smile. Levi softly chuckles at that, then lowers his gaze to avoid Erwin’s eyes.

The door soon slides open with a rattle.

“Shit.” Levi and Erwin gape at each other in alarm.

Erwin picks up a random book lying on the counter and pretends to read with his back turned to the aisle, while Levi quickly slides off the counter to head behind the till.

Levi gapes upon recognizing Armin and Mikasa across the aisle. He awkwardly clears his throat, while Armin and Mikasa briefly exchange scandalized looks.

“Hey.” Levi says trying his best to keep a stern tone. _Oh fuck. I’m still wearing the glasses_. He quickly snatches them away from his face and sets them atop the counter, slightly pushing them closer towards Erwin. Erwin, in turn, not-so-subtly picks up the glasses and puts them on. “So I thought you said you’d be back past dinner time,” Levi says, clearing his throat as he addresses Mikasa. “Also, the store is already closed. What’s he doing here?” Levi vaguely gestures towards Armin.

“Hm.” Mikasa eyes them scrutinizingly. “We just finished dinner earlier than I expected. Also, I brought Armin along to help me carry the groceries.” She carefully sets down the grocery bags she had been carrying on the floor. Armin does the same. “The real question is…” Mikasa says, stone-faced as she points towards Erwin. “...what’s he doing here?”

“Professor… Smith?” Armin gulps.

Erwin buries his face into the book in defeat. Levi swears under his breath as he trails his palm down across his face. Slowly, Erwin turns to face the aisle with a deflated sigh.

“Oh, good evening, Armin. It’s nice to see you here.” Erwin, adjusting his glasses, gives him a polite, amiable smile. “Levi here was just telling me that we frequent the same bookstore.” Erwin gestures towards Levi. _No shit, it’s the only bookstore for miles around,_ Levi thinks. “It’s quite a surprise that this is the first time we’re meeting here. Oh-- and before I forget, I have something for you here.” Erwin beckons towards him. 

“Oh. Ok.” Armin briefly glances at Mikasa. She shrugs. And then he heads towards the till. He scratches his head awkwardly as he stands in front of his professor.

“I apologize for the delay-- it slipped my mind to return your midterm paper just before I took my series of sick leaves.” Erwin rummages a bag sitting atop the counter. “And by the way, thank you for filling in for me. The students from my undergrad classes said you have a knack for making literary theory easier to understand,” he chuckles. “Let’s see here… yours was on H. Isayama’s novel The Other Side of the Ocean…” Erwin mumbles, picking out a sheaf of papers from his bag. “Right, this is the one. Here.” Erwin hands him his midterm paper. “You did well, Armin.”

“Oh. Thanks, professor.” Armin is dumbstruck as he reads the professor’s comment on his paper:

_Loved your take on Isayama’s depiction of a political dystopia! Your use of Mill’s Utilitarianism to analyze the key characters’ motivations was indeed apt for this text. Would be thrilled to read more from you. Well done, Armin!_

Below the professor’s note, there’s a printed stamp of a smiling cartoon octopus raising one of its tentacles in a comically unrealistic thumbs-up. ‘Tentaculous!’, the text reads beside the octopus.

 _Tentaculous?_ Armin isn’t so sure if he’s just so overwhelmed that he couldn’t register what other word this was trying to make a pun out of, or if this was simply meant to be a made up expression of exclamation. Was it making a tentacle pun out of the word ridiculous or marvelous? If it were the former, that just wouldn’t be apt for praising a student’s paper, would it? He could ask the professor right now, but then seeing as he’s on the verge of tears-- joyful ones at that-- now probably isn’t the best time. Oh well, at least he got an A. 

He smiles up at his professor with light in his eyes.

Erwin, in turn, ruffles his hair with a proud smile.

Meanwhile, Mikasa raises an eyebrow questioningly at Levi. Levi rolls his eyes in turn, realizing he still owes her an explanation after this.

**Notes for the Chapter:**

> one reason why i wrote this entire fic is bc i just wanted to overindulge myself in my favorite underrated aot character dynamics (arumika + their subtle parallels with erwin and levi; levi and mikasa being distant relatives; armin and erwin’s almost-father-and-son-but-not-really-because-they’re-not-related dynamic)
> 
> another reason is ERURI


	6. Chapter 6

Mikasa trudges through the shallow waters just a little ways away from the shore with Armin in tow. She ceases to scoop up a seashell underwater as the wind picks up and the fabric of her clothes flutters against her skin.

“Have you… have you ever tried putting the seashell against your ear?” Armin asks when he catches up to her.

Mikasa turns to him.

“I have.”

Armin nods. “What do you hear?”

“Well, I know that it’s just all the sounds around you resonating within the hollows of the shell...” Mikasa hums. “But… when I was a kid, I always thought it sounded like… talking. Like the sea was trying to say something.”

Armin smiles at that. “What did you think it was trying to say?”

Mikasa shakes her head. “I could never really understand what… but I was convinced there was definitely... something.” She shrugs. “Well… I was just a kid anyway.” She thoughtfully eyes the seashell in her hands, tracing its contours and hollows.

Armin nods. “I guess it’s the same for me. It’s just that… I thought the sea was shy. That’s why it was murmuring its words.” He chuckles, scratching his head sheepishly. “It’s as if… as if there was something they wanted-- _needed_ to say, but it just never surfaces… and yet, it _is_ there. Perhaps coursing just a little below the surface,” Armin says as he gazes down at the shallow waters, idly playing with the sand with his foot.

Mikasa puts the seashell to her ear, holding onto it with both hands. Armin looks up to watch her. There’s a pensive look on her face for a while, but soon quirks into something else. She furrows her brows and clicks her tongue, displeased. She puts the seashell away from her ear and eyes it with a scowl. 

“How annoying,” she says with another click of her tongue. Armin chuckles at that and playfully thinks that he was reminded of Levi for a second.

The gust of wind grows slightly stronger and Mikasa stumbles a little, dropping the seashell from her grasp. “Oh!” she yelps as she finds her footing.

Armin leans over, dipping his hands into the water to search for the seashell.

“It’s fine,” she says. Mikasa watches him pensively. “You don’t have to look for it.”  
  
“Oh. Ok,” Armin says, looking up at her.

Then, she, too, leans over and dips her hands into the water. Below the surface, she cups Armin’s hands together in hers and then scoops up some water with them. Carefully, Mikasa lifts their hands as she straightens herself, with Armin following suit. She leans her face closer to their hands, studying her reflection in the water-- within Armin’s cupped palms.

“Huh. I think I see myself better here… I’m not sure why.” Mikasa furrows her brows as she tilts her head in thought, then looks at Armin. “You’re blushing.”

Armin abruptly straightens himself. “Oh, what? I, uh, I’m sorry. It’s just-- it must be the sunset-- it’s--”

Then Mikasa lets out a soft chuckle. “Why are you saying sorry?”

“I… I don’t… know.” Armin bows his head sheepishly.

Mikasa briefly glances down at her reflection in his cupped hands again before finally letting go. She pulls away, hands now behind her back, then gazes down at the gentle crashing of waves against her legs. She gives Armin a furtive glance and sees him still blushing.

Soon, the tide ebbs precipitously and she stumbles.

“Mikasa!” Armin seizes her by the arm and pulls backward in an attempt to steady them both. However, a pull under the surface eventually sends them both crashing into the water-- falling on their backs with a sharp splash.

Mikasa’s face twitches from the impact as she begins to sit up.

“Mikasa, are you ok?” Armin says, leaning against his elbows as he struggles to lift himself up from the water.

“Yeah,” she says, finally standing as she wrings out the water from the edges of her blouse and the rolled up cuffs of her pants. She then stretches out a hand at Armin to drag him out from the water. With their hands clasped, Mikasa pulls him up and then leads him back towards dry land.

They sit silently on the shore for a while as they watch the sun sink into the horizon. The wind picks up again. Armin soon scoots closer towards Mikasa, hugging his knees close with his chin propped up on them. She takes note of their proximity and turns to face him. When their eyes meet, she feels her pulse race. Mikasa clutches a hand at her chest. There’s a lump in her throat and warmth in her cheeks. Mikasa lifts a hand and slowly reaches towards him. When she gently places a palm against his cheek, Armin sheepishly lifts his head from his knees. Warmth settles into her palm despite the cool drops of water still sticking to her skin.

“It’s not the sunset,” Mikasa says.

And that’s when she realizes it: She’s been swept away by the undertow. She isn’t so sure how long exactly it’s been there-- just how long it’s been coursing below the surface.

Her hand falls from his face.

“I know it isn’t,” she continues with a slight shake of her head. Mikasa takes Armin’s hand in hers-- holding his wrist with care, and then places his palm against her cheek. “Look, I’m the same.”

“Oh.”

Armin gapes slightly in realization.

Mikasa soon lets their hands fall onto the sand and turns to face the horizon. Armin watches in wonder as the cold sea wind sweeps through her hair and the sunset paints her skin with warmth. There’s a hint of a smile on her face as she leans her head against his shoulder.

A tide rises in his chest.


	7. Chapter 7

“Oi.” Levi nods to Mikasa when she returns to the store. “Armin dropped by earlier,” he says perfunctorily in the middle of arranging some books on the shelf.

“Ok. Did he say anything?” Mikasa heads back to her spot behind the till.

“Not much,” he says simply. “Just bought a book.”

They go about their business in silence after that. Mikasa doesn’t know why Levi had to mention such a mundane occurrence in the shop. Ok, so Armin dropped by while she wasn’t around. What’s the deal? Of course, Mikasa would be lying to herself if she said that was a useless piece of information. It was _something._ Something that concerned Armin-- so of course that wasn’t nothing to her.

When Mikasa picks up her book from the counter, that’s when she realizes something was a little odd. Her book was closed, despite clearly recalling that she had left it open-- pages facing down on the surface of the counter. Had Levi possibly moved it while she wasn’t around? Mikasa flips through the pages. How annoying. She hadn’t marked the page where she left off so she’d have to--

And there she sees it-- a flattened paper boat stuck in between the pages where she had left off earlier. It seems to have been made out of used paper seeing as it’s filled with handwriting and a few ink blots here and there.

She squints at it, examining it carefully in her hand. Suddenly, she has an inkling of where this could have come from. Levi had strangely mentioned Armin earlier-- possibly clearly knowing that that piece of information wasn’t nothing to her.

Carefully, she unfolds the paper boat.

‘Hi, Mikasa!’, the first line reads.

_Oh._

Well, no doubt about it now-- this was clearly _something_.

She continues to read.

#

Hi, Mikasa!

I know you said you think I’m the type to write cringey love letters, so here’s me trying to disprove that. Although I’m probably already failing because (and I’m so sorry to be warning you about this) I’m about to reference Shion Miura’s novel here in a love letter. I guess you were right about me-- that I’m not so different from Majime and how he quoted all those classical poets in his letter in a pathetic attempt to confess his feelings for Kaguya. (╥_╥)

So here goes nothing. (╮°-°)╮┳━━┳ ( ╯°□°)╯ ┻━━┻

\--

In The Great Passage, Miura likens the dictionary to a ship-- that which sails the sea of words. Those who embark on it navigate through the waves-- probing the waters in an attempt to capture the very meaning of these words as accurately as possible, taking to consideration even the slightest of nuances. These voyagers do so because they want to get something across-- by putting the flurry of their thoughts, feelings, and memories into words most fitting. They want to _get across to someone_ \-- and for that someone to understand them with utmost depth and clarity. 

I, too, am a voyager. And such is the reason I am writing you this letter, Mikasa. I want to get across to you, like a ship longing for its harbor. The harbor is the ship’s home-- the sole place where it is _most understood_. And thus, I, a voyager of this ship, can only find solace if I am able to sail across this sea of words to get to you.

So here it is, in the most accurate way I can put it: I’ve grown enamored of you, Mikasa. You are my favorite person.

Funnily enough, I remember you saying that you weren’t good with words and I think the same of myself as I write this. Whatever your response to this would be, nevertheless, I’m willing to accept it-- to understand you as best as I can. And if, in turn, I may not be your harbor, I’m at least willing to be someone, somewhere you can find a little solace in-- even if I may not be the best at it.

Love,  
Armin

P.S. So maybe I should have asked Professor Smith to advise me on writing this letter instead of my thesis (╥_╥)

#

Mikasa silently gapes at the letter after reading it. She rereads it a few more times, then eventually folds the letter back into a paper boat-- following the creases Armin had already made. 

Mikasa tries to compose herself and decides to get back to reading her book, the paper boat bookmark now slipped in between a different random page spread. She finds herself having to reread the first sentence on the page where she had left off-- again and again, her mind too stubbornly distracted to comprehend its meaning. 

Mikasa lets out a frustrated sigh. She ends up burying her head in between the pages with a stupid smile on her face.

***

There’s a light knock on wood from behind her on the porch. Mikasa turns from her side to lie on her back instead, resting the book she had been reading on top of her chest. She meets Armin’s eyes as he leans beside the frame of the door slid open.

“Uhmm, hey,” he starts, timidly darting his eyes to the side.

“Hey.”

Armin’s eyes wander towards the cover of the book in recognition. It’s the same book from days ago-- where he had put the paper boat bookmark.

Mikasa sits up, then pats lightly on the spot beside her on the porch as she gives him a brief glance. Armin settles down beside her, his legs dangling from the porch. She scoots a little distance away from him, and then lies back down again with her head perched on his lap. Mikasa gazes up at him with a soft, musing look in her eyes.

“So, uhm…” he says, nervously scratching a finger on his temple. Armin turns his head to the side to avoid her gaze.

Mikasa reaches a hand up to cradle his cheek, gently urging him to face her. “It’s fine. You got across.”

“Oh. That’s-- I… I’m glad...”

“I’m still no good with words, but…” She furrows her brows in thought. “...in the most accurate way I can put it…” Mikasa echoes his words. “...I like being with you. I like you,” she says simply.

Armin swallows nervously. He gapes at her, cheeks flooding with warmth. He places his hand over hers.

“...Did that get across? Or...?” she asks with a light chuckle.

“Y-yeah. It did. I’m just… really glad.” He heaves a breathy sigh, as if he’d been holding his breath for too long.

Mikasa gently lets her hand fall from his cheek, along with his own. She gives him a reassuring smile.

Armin eventually finds himself leaning closer, timidly reaching towards her. He entangles his fingers in her hair, combing through them delicately. “You know, I… I always thought you were really… pretty. I was just too shy to say it.” 

There’s a faint blush on Mikasa’s cheeks, and then she lets out a small laugh as she raises the book to hide her face beneath it. Armin reaches towards the book, lightly pushing it away so her eyes are at least in view. He gingerly pushes away the strands of hair on her forehead to get a better look at her eyes. Slowly, Mikasa lowers the book to rest it back on her chest. Armin gives her lips a furtive glance. She notices.

“Mikasa, can I...”

“You can kiss me.”

“Oh. Ok.” He swallows nervously, then briefly darts his eyes to the side. He takes a deep breath, closing his eyes. Slowly, he leans his face closer as he cradles her cheek in one hand-- gently urging her to lean forward and tilt her head slightly. Mikasa closes her eyes. And then he places a soft kiss on her lips.

A tide rises in his chest. The cold wind picks up and strong waves crash onto the shore.

When they pull away, their eyes meet in a loving gaze.

Mikasa soon rests her head back on his lap and he continues idly combing through her hair.

“Armin?”

“Yeah?”

“I’m feeling sleepy. I think... I’ll take a nap.”

“Ok.” He lets out a light chuckle.

Mikasa slowly closes her eyes.

Armin leans closer and places a chaste kiss on her forehead.

He watches the waves before them come to a lull and soon finds himself leaning on the wall behind the porch. 

When he sinks into a deep slumber, a memory finally resurfaces in his dream.

**Notes for the Chapter:**

> since this is such a rare pair heres some additional content 😎 i made an arumika playlist which goes exactly with the mood and themes of this fic:  
> [arumika playlist](https://open.spotify.com/playlist/48scfbiYdXBCwpFliDFJna?si=_iwtGBbhQfOF-m5P4TvGtA)
> 
> i also drew the playlist cover/arumika fan art for this^ playlist, so if u just want to see the art, that's fine too ig... but i will say u are missing out on additional arumika feels if u dont listen to it dhdjsksk 
> 
> ***i finally drew fan art based on this fic (this is different from the one in the playlist):  
> [arumika fan art](https://twitter.com/pieleth_/status/1359816453461975044?s=20)


End file.
